How to Install Cement Board to Waterproof Block Walls
- 1). Measure the area of the waterproof block walls where you plan to install cement board. Cut the cement board down to the proper size using a straightedge to form straight lines and a utility knife. Score along the straightedge with the knife and cut through to the reinforcing mesh beneath the top panel. Snap the cement board along the cut line, and it will break cleanly. Run a rasp over the edge if any edges are rough.
- 2). Clean the waterproof block wall by wiping it down with soap and water to ensure any debris or dirt is completely removed.
- 3). Use a V-notched trowel to apply a thin layer of organic adhesive to the block wall. Press the cement board panel into place immediately. Run your hand over the cement board to ensure even contact with the block wall.
- 4). Install flat-head concrete screws around the perimeter of the cement board. Use a hammer drill to form a starter hole and a screwdriver to attach the flat-heads into place. Install additional screws every 8 inches throughout the cement board.
- 5). Repeat the process until the wall is completely covered.
- 6). Fill in the gaps between the boards and the tops of the screw heads with latex-fortified mortar. Smooth the mortar to the level of the cement board for an even finish.
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